Treatment of hydrocarbons



Sept. 8, 1931. J. c. cLANcY flrmA'lMENT 0F HYDRocARBoNs Filed April 29. 1930 Patented sept. s, 1931 l I 1,822,127

UNITED STATES PATENT ori-Ica JOHN COLLINS CLANCY, OF .ASB'UBY PARK, NEW JERSEY TREATMENT F HYDRCABBONS i Application. led April 29, 1930. Serial No. 448,413.

My invention relates to the catalytic theralone as the molten starting material, or when mal decomposition of the heavier hydrocara molten mixture of sodium cyanide and sobons with a molten catalyzer, and its prindium thiocyanate was employed as the startcipal objects are to increase the yield of aro-*- ing material for contacting the oil feed stock 8 matic hydrocarbons and to employ as the for the production of lower boiling point 55 catalyzer a cyanogen salt of a'metal in a hydrocarbons. fused mixture of such a salt and another salt I have therefore sought andhavefoundsuch which will prevent the generation or liberaa combination of substances as will not only tion of hydrocyanic acid from such catalyzer permit of a reduction in the quantity of alka' l0 when the latter, at al cracking temperature, is linous metal cyanide in molten compositions 60 contacted with the hydrocarbon material to employed for the catalytic thermal decompot be treated. The present invention is an im-` sition of a given quantity of the oil feed provement on my prior U. S. Patent No. stock for the production of lower boiling A1,658,116, February 7, 1928-entitled Procpoint hydrocarbons, but which will further l ess of cracking oils. ail'ord a means of preventing the evolution or 65 In the aforesaid prior patent I have degeneration of hydrocyanic acid gas from the scribed and claimed different phases ofa cyanide contained insuch compositions whileprocess, and-some apparatus for practising lthe latter are contacting with the oil under the samefinvolving the cracking .of heavier treatment, irrespective of whether such oil hydrocarbons by contacting them, in the contains relatively high percentages of sul- 70 presence of a metallic catalyst, with molten phur or acid compounds'or both; moreover, compositions consisting predominantly of while satisfactorily accomplishing these realkali metal cyanide, (a preferred composisults, I have succeeded in going still further, tion `being a molten mixture of sodium cya- `in that my present process not alone affords a nide and sodium thiocyanate) the carbon reductionin the quantity of cyanide, but ac- 75 separated out in the treatment of the oil and tually gives more than 50% yield of aromatic l which accumulates in the molten material behydrocarbons and 20% gasoline from,y for p .ing discharged from the converting system as example a kerosene oil stock without excesa carbon bearing molten magma; continua- A`sive formation of carbon and fixed gases. 80 tion of the process being carried out in a The present invention is based upon the 80 cycle as by filtering the accumulated carbon discovery that an alkaline reacting substance from the molten material and employing the or reagent such, for example, as sodium carlatter over and `over again after having, if nate in a fused mixture of such a salt and necessary, been replenished with f esh soyan alkalinous metal cyanide, such for indium cyanide for the treatment offurther stance, as sodium cyanide, has the effect of 85 quantities ofthe oil feed stock. On continued preventing the evolution or generation of use of this method, however, a diiculty behydrocyanic acid gas from the cyanide comcame apparent, unforeseen when operating pon'entof said mixture when the latter is on the small scale; namely that hydrocyanic employed as a molten catalyzer for contact- 4 acid gas was evolved or generated from the ing hydrocarbon oils or the vapors thereof 90 molten material, thereby causing destruction for the production therefrom of lower boilnot only of alkali metal cyanide, but also ing point products. The protective. action creating a hazard on account of the poisonous of the alkali metal carbonate, when admixed nature of the evolved gas. Investigations in suiicient-quantity with the cyanide, being have shown that alkali metal thiocyanate so complete that proportionate quantities of 95 was responsible for the` stated generation of hydrocyanic acidy gas may be bubbled into a hydrocyanic acid gas, whether such thiocybath of the fused mixture to react with the anate was formed 4through interaction of the alkali carbonate to form alkali metal lcyaoil sulphur compounds with the molten sonide without escape of hydrocyanic acid from dium cyanide, as when the latter was used. the molten bath. VA preferred starting com- 1 00 position for the molten catalyzer material.

5 below 450 C., this melting point usually becoming lower as the molten catalytic -material desulphurizes the oil feedu stock with more or less formation of alkali sulphides and alkalithiocyanates and separation of carbon like material in the molten catalyzer.

Experimentation has shown that it is not necessary to filter out or remove the carbon (as described in my aforesaid prior patent) from the molten material until it accumulates therein to near its saturation point, and then removing only a portion of such carbon as I have discovered that, the carbon like material formed from the oil treatment exercises not only a specific catalytic effect in 'conjunction with the molten catalyzer to increase its activity in promoting the afore- .said high yields of aromatic hydrocarbons, but it also enables the splitting temperature Yto be lowered` thereby diminishing carbon formation and decreasing the formation of fixed gases when such a carbon bearing molten catalyzer is employed for the treatment of further quantities of the oil feed stock.

Furthermore, I have found that the employment of a metallic catalyst in coni unction with the molten catalyzer compositions referred to, is not necessary for 'thestated oil cracking reaction and that the said molten cyanide compositions even when contaminated with relatively large percentages of sulphur and other impurities derived from the oil stock do not decrease the activity of the molten catalyzer provided that sodium carbonate and sodium cyanide are the predominating components of said catalyzer. In fact, said impurities increase the catalyzer activity.

I may use any of a number of catalytically operating alkalinous metal cyanogen compounds which are fusible at relatively low temperatures in admixture with an alkalivnous metal carbonate or a plurality of different compounds of one or more cyanides 1n admixture with one or more alkali carbonates. Ordinarily I find that alkali metal cyanides are better than the alkaline earth cyanides and I shall therefore speak more specifically hereinafter of the alkali metal cyanides and alkali metal carbonates. Sodium cyanide is well adapted for my present process. Potassium vcyanide is also well adapted. Mixtures of sodium cyanide with potassium carbonate or mixtures of potasslum cyanide with sodium carbonate form very low melting point `eutectic mixtures which may be used for special purposes but offer no substantial advantages over a eutectic mixture of sodium cyanide and sodium carbonate for general use as the starting molten catalyst material. Obviously, cyanogen compounds, such as sodium cyanate,

potassium cyanate or other oxygen bearing cyan'ogen compounds which become reduced to cyanides in the presence of carbon or a hydrocarbon at the temperature maintained in the cracking operation might be employed in combination with an alkali metal carbonate as the starting material but such mixtures would offer no material advantage over simple mixtures of alkali metal cyanide and alkali metal carbonates. Similarly, alkali metal hydroxides such as sodium hydroXide orl potassium hydroxide might be used in starting material in lieu of the corresponding carbonates but, here again, no advantage from their use would accrue as during the operation of the process such hydroxides are transformed to their corre spondent carbonates.

In one specific embodiment of my invention as applied to anyl high boiling hydrocarbon oil, such as the various high boiling crude oils and derivatives thereof; pressure distillates, fuel oil. still residuums, shale oil, gas oil, tar oil and even cracked gasoline and similar cracked petroleum products, I first charge a mixture comprising 35% sodium carbonate and 65% sodium cyanide, preferably in the molten condition` into a lclosed vessel or still made of any suitable material, such as chrome iron alloy. The charging is continued until the still is about half filled with the starting molten eutectic mixture which comprises the molten catalyzer. Alternately, the molten catalyzer employed may be that Droduced by treating the cyanide' containing residue of a previous oil cracking and distilling operation with ammonia, as hereinafter referred to. The catalyzer is maintained in the molten condition within the still by the application pf heat thereto. The oil. for example, a gas oil preferably though not necessarily in the vaporized condition. is introduced at a low point in the still so that it enters well below the surface of the bath or depth of the molten catalyzer, the latter being maintained at a temperature between 500 C. and 650 C. or higher. A good expedient is to provide a shallow depth layer of molten lead underlying the molten cyanide mixture and have the oil feed pipes enter beneath the surface of the same so that in case of stoppage of the oil in the feed line, with a resulting partial vacuum therein, the molten lead is sucked up in lieu of the molten cyanide, the latter being of less specific gravity otherwise is sucked up out of the heat zone solidifying in and clogging the oil line, the former owing to its high specific gravity is not sucked up out of the heat Zone and on resumption of the oil feed, the molten lead is forced out of the oil feed pipes leaving them clear for continuation of the oil treatment. As the vaporized oil is injected, it commingles with the molten catalyzer and the generated vapors resulting from such contact pass upwardly through the depth or bath of the molten catalyzer, said vapors upon condensation gaged its quota of oil, said quota yield a distillate containing a high percentage of aromatic hydrocarbons. When the molten catalyzer charge in the still has endepending upon whether the proportion of separated carbon suspended in the molten material has formed therewith a free flowing cyanide containing distillation residuum easily disvchargeable from the still as more or less partly spent catalytic material; usually, however, when the carbon accumulates to near its saturation point, as for example, to 75% of carbon in the molten mixture of sodium carbonate and sodium cyanide, I discontinue the feed of the oil stock to the still but continue the heating thereof until the said partially spent catalytic material is ready for discharging. When this occurs the charge is finally dumped and replaced by a new one, the new one being preferably a catalyzer produced by treating partially spent catalytic material from a previous oil cracking operation as referred to hereinunder. -The time and usefulness of a charge may be prolonged somewhat by making, fresh cyanide. plenished and even with relatively high compounds functions v sion of further quantities of oil stock tolow boiling aromatic hydrocarbons provided, `as noted, a sufficient quantity of alkali metal carbonate is present in the said replenished catalyzer. During 'the operation of the process the distillation products are suitably additions thereto of though contaminated percentages of sulphur fractionated or condensed into products desired for motor fuel or gasoline like material. The heavier oils separated by such fractionation being returned to the-process for conversion into lighter oils. The uncondensable gases which escape from the filial y condensing system being used, in part at least for heating purposes, etc.

The discharged distillation residues or partly spent molten catalytic material which has become unsuitable for further use in the oil conversion may be regenerated by treating it in a cyanide making retort, according to the well known Beilby process for manufacturing cyanides froma molten mixture of alkali cyanide, alkali carbonate and carbon. For example, by simply'heating the partially spent molten catalyzer between 800O C. to 900 C. and bubbling a proportionate quantity of ammonia therethrough, a cyanide forming reaction takes place resulting in a disappearance of carbon in proportion to the quantity of alkali carbonate and other alkali compounds in the spent material, with the production of a corresponding proportion of alkali cyanide. Usually, however, about 85% of the original carbon content of the spent alloy and having In fact, a charge thus rel actively in the Conifer-- material remains unconsumed butin activated form. In this yway regenerated catalytic material is obtained containing active carbon which after admixture of the same with its quotav of alkali carbonate, produces a catalyzer having much greater catalytic activity than one prepared from fresh starting materials. v

In another embodiment of my inventionI operate in a continuous manner'andemploy a continuous feed of previously prepared molten catalytic material so as to obviate, in part at least, the overheating of Vthe walls of the retort wherein the molten catalyzer adjacent thereto becomes more or less superheated, resulting in a disproportionate formation' of carbon and fixed gases at the cracking temperature employed. In carrying this embodiment of my invention into practise an arrangement like a column still or scrubhing-tower retort is employed. This retort being preferably constructed of chrome iron a filling of packing units for filming out the molten catalyzer, saidj a highly packing units being composed of good heat ill)l conducting material,- such .for example, as masses of iron shaped in the form of the so called Raschig rings,about one inch` in diameter.

In the drawing which forms a part hereof, I have exemplified an apparatus whereby the process maybe carried into effect.

IIn said drawing, the figurev shows a vertical section of a column still or retort containing th'e packing units, and provided with gas and other connections, hereinafter described.

The retort 1, filling of packing units 2, is heated in part by the heat contained in the previously prepared molten cyanide and alkali carbonate mixture 3, and is kept molten in the funnel charging hopper 4by the eX- ternal heat supplied b v furnace A. The molten cyanide material flows over the edge of the trap pot 5, and trickles downwardly through the packing units countercurrent to a flow-of hydrocarbon oil vapor supplied through pipe 6, from an adjoining still or the oil may be sprayed directly into the colum'n `still at or near the middle thereof as at 6. The lower end of the column still or retort is closed to the atmosphere and is provided with the sealed outlets 7 and 8 for the molten lreaction productsand unvaporized oil respectively. At the upper end of the column still or retort is an outlet 11, for the hydrocarbon vapors and gases resulting from the oil treatment in contact with the molten catalyzer material filming over the packing unit-s. Molten cyanide catalvzer material and i roo the retort as at 11,9 and 10 at top and bottom respectively, the temperature of the column still or retort being maintained and controlled by the heat supplied by the furnace B.

lt is obvious that, the discharged molten material may be circulated through the column still until it contains sufcient carbon in suspension to justify its treatment for the regeneration of the catalytic material by treatmentwith ammonia at cyanide forming temperatures in the manner already described.

The vapors and gases emanating from the retort may pass into a dephlegmator, which may be suitably arranged to yield as fractions a gas oil or any unconverted heavier oil. Either or both of these products may be returned to the reaction zone of the retort for further decomposition if desired.

The lighter oils or volatile spirits are condensed in either a dephlegmator or condensor of any of the well known types as already referred to.

The drawing accompanying this application isthe same as the one shown in my said prior patent; it is reproduced here for the purpose of illustration and reference. Many other types of retort or stills which employ fused material as a cracking instrumentality are applicable provided they are constructed of suitable material, such, for example as chrome iron alloy or similar material which can withstand the action of the molten catalyzer.

The stated cracking operation may be carried on under pressure greater than atmospheric, at atmospheric pressure or under reduced pressure. However, when operating the above described column still or scrubbing tower retort I prefer to operate at a pressure not substantially-higher than that' which is necessary to force the generated vapors and gases through any of the well known types of dephlegmators and condensing systems. Pressure may be used but it has been found that the product contains a relatively large content of oleines without a proportionate increase in the aromatic hydrocarbons. Temperatures from 450 C. to 650o C. and higher may be employed but the best results have been obtained between 500 and 530 C. The process may be operated above 650 C. but larger yields of fixed gases are obtained and to avoid this, the lower temperatures are employed.

From the presence. of

` v pounds, such as sodium sulphide and sodium crease in proportion thiocyanate in the partially spent molten catalyzer material it is obvious that the components of the latter act as desulphurizing agents while concurrently functioning as the catalyzer to promote the stated oil conversion reaction. The percentage of said alkali sulphur compounds, however, does not into the percentage of alkali sulphur com-` sulphur compounds in the oil which has been contacted or treated with the molten catalyzer. For example, after bubbling a measured quantity of a Mexican petroleum pressure distillate, assaying 2% sulphur, through a three foot depth of the molten catalyzer contained in a four inch diameter retort, there was obtained a condensate which after the usual treatment with sulphuric acid and alkali assayed less than one tenth of one per cent sulphur. Analysis of the partially spent catalyzer material, however, showed 1t to contain less than 5% ofthe sulphur content of the original oil stock or distillate after figuring proportionate quantities of the oil and catalyzer material. condensate prior. to its treatment phuric acid and alkali showed it to contain nearly 'of the sulphur content of the original oil or distillate. Analysis of the evolved gases which escaped condensation showed them to contain nearly 30% of the sulphur content ofthe oil feed stock (pressure distillate), the sulphur in said gases being present chiefly in the form of hydrogen sulphide. Experimentation, however, has shown that the proportion of sulphur abstracted from the oil by the molten catalyzer material varies according to the nature of the sulphur compounds in thev oil feed stock, It has also been found that by admixing hydrogen and particularly ammonia with the vapors of the oil feed stock a muchlarger proportion of the sulphur content of the oil is transformed into hydrogen sulphide, irre- Assay of the with sul- -spective of the nature of the sulphur compounds present in the`oil feed stock or the vapors thereof.

In the regeneration ofthe partly spent catalytic material by the action of ammonia thereon at cyamde forming temperatures, the alkali sulphur compounds therein are eliminated in the form of hydrogen sulphide. For example, sodium thiocyanate 1s reduced to cyanide by the action of the ammonia, the hydrogen of the latter combining with the sulphur to form hydrogen sulphide. Alkali sulphides react with the ammonia in the presence of the carbon forming lalkali cyanide with the elimination of hydrogen sulphide. Traces of sulphides remain, but as pointed out these together with the unconsumed carbon produce catalytic material having much greater activity than fresh starting materials.

I lay' no claim to the regeneration or reclamation of the cyanide except insofar as to produce a. catalyzer from the spent material as already described. It is to be understood that the details of loperation herein set forth are given merely for the purpose of affording a better understanding of my invention and that the invention is limited only by the scope of the appended claims.

c tiall yso .which maiala? What I clainr as my invention is:

1. A process of treating a hydrocarbon oil comprises vaporizing the hydrocarbon oil and cracking the vaporized oil by contact with a catalyzer comprising-a cyanogen salt of an alkalinous metal in a molten mixture of such a salt and another salt which is capable of preventing the decomposition products `of the oil from liberating hydrocyanic acid from such mixture while the latter is decomposing the oil at a cracking temperature.

2. A process of cracking and distilling higher boiling point hydrocarbon oils for the production of lower boiling point hydrocarbons which comprises, contacting such a higher boiling point oil with a molten catalyzer produced by treating with ammonia at cyanide forming temperatures the cyanide containing distillation residuum resulting from the-cracking of a hydrocarbon oil with a moltenmixture of alkali metal cyanide and alkali metal carbonates, said catalyzer having suliicient alkali to to prevent the decomposition products of the oil under treatment from liberating hydrocyanic acid from tlie molten catalyzer while the latter is maintained at a cracking temperature.

3. A process of treating hydrocarbon oils which comprises subjecting `,such an oil to catalytic thermal decomposition b contacting it with a cyanogen salt of an alkali metal in a molten mixture of such a salt and an alkaline reacting metallic salt which is capable of preventing the liberation of hydrocyanic acid from suoli mixture While the latter is decomposing the oil at a cracking temperature. 4. A process ofttreating hydrocarbon oils which comprises subjecting such anoil to catalytic thermal decomposition by contacting it, ata cr'ackingtem erature, with a molten catalyzer produced y treating'the pary spent cyanide containing catalyzer from a previous oil cracking operation with ammonia at cyanide forming temperatures, said catalyzer having sufficient sodium carbonate added thereto to prevent the decomposition products of the oil being treated from liberating hydrocyanic acid from said molten catalyzer while the latter is maintained at a cracking temperature.

he process of cracking hydrocarbon material having a lower aromatic hydrocarbon content than the desired products to motor fuel having a relatively high aromatic f hydrocarbon content which comprises, bringing said hydrocarbon material into contact, at a cracking temperature, with a molten mixture of alkali metal carbonate and alkali metal cyanide containing accumulated carbon like material separated out in the cracking operation, said mixture containing sufficient alkali metal carbonate to prevent the decomposition products of the hydrocarbons metal carbonate added thereunder treatment from liberating hydrocyanic acid from the molten mixture While the latter is maintained at a cracking temperature, and condensing the evolved vapors.

he rocess of crackinghydrocarboiis having a igher molecular weight than the desired products to gasoline like material containing relatively high percentages of aromatic hydrocarbons 'which comprises bringing the hydrocarbon vapors into contact, at a temperature above 400 C., with a molten eutectic mixture of alkali bonate and alkali metal cyanide, and condensin the evolved vapors.

7. Te process of treating a hydrocarbon oil which comprisesvaporizing the .hydrocarbon oil and cracking the vaporized oil by contact with a catalyst comprising sodium cyanide in a molten mixture of such a salt and another salt which is capable of preventmetal caring the liberation of hydrocyanic acid from taining sulphur for the production of lower oiling point desulphurized hydrocarbons which comprises, contacting such a higher boiling point oil with a molten catalyzer produced by treating with ammonia at cyanide forming temperatures the cyanide and sodium carbonate containing distillation residuum resulting from the ycracking of a hydrocarbon oil with a molten mixture of sodium carbonate and sodium cyanide, said catalyzer having sufficient sodium carbonate added thereto to prevent the evolution of hydrocyanic acid from said catalyzer while the latter is decomposing ,the oil at a cracking temperature.

9. The process of cracking yhydrocarbon material bon content than the desired products to having a lower aromatic hydrocariosal motor fuel containing relatively large perf centages of aromatic hydrocarbons which comprises, bringing said hydrocarbon material into contact with a molten mixture of sodium carbonate and sodium cyanide containing accumulated carbon like material separated out in the oil cracking operation, said mixture containing sucient sodium carbonate to prevent the generation of hydrocyanic acid from said molten mixture'while the latter is decomposing the oil at a cracking temperature, and collecting the lighter oils ormed as a result of such cracking.

10. In a process of manufacturing' lower boiling point oils from higher boiling point hydrocarbon oils containing sulphur compounds the steps comprising, contacting such a higher boiling point oil with a molten mixture of sodium carbonate and sodium cyanide maintained at a cracking temperature, the iliof its constituents; continuing the contacting of the oil with the molten mixture until a stage is reached wherein the carbon separated :from the oil accumulates to its saturation point in the molten mixture, and oondensin the evolved vapors.

11. process of )treating hydrocarbon oils containin sulphur compounds which comprises su jecting such an oil to catalytlc w thermal decomposition by contacting it with a molten mixture of sodium carbonate and sodium cyanidein such proportions as to 've such mixture a melting point of less t an 600 C. and maintaining the same at a cracking temperature during the contact of the oil therewith, and condensing the evolved vapors.

12. The process of making gasoline like material Jrom heavy hydrocarbon oils containing sulphur compounds which comprises cracking and desulphurizing such a heavy oil by. contacting it with a. molten mixture of sodium carbonate and sodium cyanide in the presence of substantial quantitles of carbon separated out in the reaction, the sodium carbonate being present in sucient quantity in such mixture so as to prevent the sulphur decomposition products of the oil from liberating hydrocyanic acid-from the molten mixture while the latter is maintained at a cracklng temperature, and condensing the evolved va ors.

igned at Asbury Park in the county of Monmouth and State of New Jersey, this 22d day of April, A. D., 1930. JOHN COLLINS CLANCY. 

